<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <link rel="stylesheet" href="./index.css">
  <style>
    .father {
      position: relative;
    }

    .son {
      position: absolute;
      top: 50%;
      left: 50%;
      margin-left: -50px;
      margin-top: -20px;
    }
  </style>
</head>

<body>
  <div class="father">
    <div class="son"></div>
  </div>
</body>

</html>